$\hbar$-Expansion for Bound States Described by the Relativistic Three-Dimensional Two-Particle Quasi-Potential Equation

The $\hbar$-expansion method is used to find Regge trajectories and mass eigenvalues within of bound states the framework of the relativistic three-dimensional two-particle quasi-potential equation. The results are applied to the Cornell and power-law potentials in the problem of determining the mass spectrum of heavy quarkoniums.